This invention relates to a pressure gauge, and more particularly to a compact pressure gauge.
A conventional pressure gauge generally has a structure similar to that shown in FIG. 1, which has a rotatable sector-like member 10. As illustrated, the sector-like member 10 has a curved edge which is toothed. Accuracy of the pressure gauge depends on the precision of the small teeth of the sector-like member 10, creating difficulties in manufacturing the sectorlike member 10. Furthermore, once dust deposits on the small teeth, undesired errors will be caused in measurement. Therefore, I disclosed an improved pressure gauge (see FIG. 2) in U.S. patent application Ser. No. 938,886, which has just been granted a patent. In this improvded pressure gauge, the sector-like member 10 is replaced with a movable rack member 20. The rack member 20 has an end portion movable in a cylinder 30, and the opposite end portion thereof is provided with a rack. Although it is easier to make the rack member 20 than the sector-like member 10, the rack member 20 occupies more space due to its movement.